MADISON, Wis. >> Someone placed a noose several years ago on the locker of a Wisconsin brewery employee who opened fire on his co-workers last week, the brewery operator said Wednesday. Police quickly warned that it’s too early to conclude that racism was a factor in the attack.

Anthony Ferrill, an electrician at the sprawling Molson Coors brewery in Milwaukee, fatally shot five co-workers before killing himself on the campus last week. His motive remains unknown. Ferrill was black. Four of the victims were white. The fifth was Latino.

Milwaukee police said in a statement Wednesday that detectives are still investigating and so far “neither race nor racism has been identified as a factor in this incident.” They also said they haven’t yet found anything that suggests the victims were involved in any racist behavior toward Ferrill.

But they cautioned that the investigation into the Feb. 26 shooting is still ongoing.

“It is imperative to wait for the facts of the investigation to be released rather than speculating and generating a false narrative that could negatively impact the lives of the family members of the victims and of the suspect, as well as the employees of Molson Coors,” the statement said.

Local media have reported over several days on speculation that the attack was racially motivated, interviewing current and former Molson Coors employees anonymously complaining about longstanding discrimination against black workers.

The company on Wednesday confirmed that a noose was placed on Ferrill’s locker in 2015. Ferrill wasn’t working that day but was told about it, the company said.

Molson Coors spokesman Adam Collins said the company investigated but there was no security surveillance video showing who placed the noose on the locker. The company explained to employees that such actions weren’t acceptable and shared channels for filing discrimination or harassment complaints. He said there’s no evidence to suggest any of the shooting victims were involved in the noose incident.

Collins called the incident “disgusting” but said there’s no record of Ferrill filing any complaints with the company or the federal Equal Employment Opportunities Commission.

Christine Saah Nazer, an EEOC spokesperson, said in an email that confidentiality laws mean the office cannot confirm or deny complaints unless the EEOC files suit against an employer, “which is usually a last resort.” No suit appeared to have been filed regarding Ferrill, she said.

The Ferrill family’s attorney, Craig Mastantuono, declined comment.

Messages left by The Associated Press with the law firm representing the Ferrill family weren’t immediately returned Wednesday.

Nooses can evoke the lynch mobs that targeted black people in the South between Reconstruction and the mid-20th century.

Miller Brewing Co., which Molson Coors took over in 2008, paid $2.7 million to settle a lawsuit by black employees who alleged that racial harassment ran unchecked at its Volney, New York, plant. Among the black workers’ complaints were nooses found at the plant’s gate.

Collins said Molson Coors has “a lot of work to do to build the open, welcoming and inclusive culture this company values. We’ve already started some of that work by listening to employees over the last few days.”

He urged people to be patient while police investigate.

“It’s understandable in the absence of facts there are rumors out there,” he said. “But we have the same kinds of questions everyone else does.”

Two former brewery employees, Robert Powell and Lonnie Carl Jones, told the Milwaukee Journal Sentinel for a story published Tuesday that a few months after the noose was found, several racist notes were slipped into Ferrill’s locker.

Asked if he could confirm whether anyone put racist notes in Ferrill’s locker, Collins again said the company isn’t aware of any complaints Ferrill may have filed with the EEOC, his managers or Molson Coors’ human resources about discrimination or harassment.

Jones told the AP in a telephone interview that he worked at the brewery from 2013 until 2019. He said Ferrill mentioned to him that someone had placed an ace of spades playing card on his locker in 2016 or 2017.

“We knew what that meant,” Jones said. “It’s calling you black, like a spade.”

He said workers of different races clustered together in cliques. He noticed racist graffiti directed toward blacks on bathroom stalls and said a Hispanic employee refused to train him on how to use a machine that filled bottles with beer because he is black. He never filed any formal complaints with human resources personnel, he said, but he did complain verbally to them. Nothing was done, he said.

Jones said the culture was so toxic that it drove him to smoke marijuana and fail a drug test, resulting in his firing in 2019.

“I still get mad about it to this day,” Jones said. “What could you do? Tell HR, they say, `We’ll look into it.’ I can’t run to HR 10 times a day. … They had bad seeds and they never tried to weed them out.”

He described Ferrill as a quiet man who was focused on his work. He never fooled around because he didn’t want to give his managers any reason to fire him, Jones said.

“That man was a nice guy,” Jones said. “He wasn’t crazy. He was normal like everybody else. They (just) pushed Tony too far.”

Messages the AP left on social media sites for Powell on Wednesday weren’t immediately returned.